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C is for Cryptography
You can make an online card payment in a single click.
The communication is secured: a pirate intercepting the transaction would not see anything usable, just a series of seemingly meaningless figures.
Your card number has been converted using a procedure known as “encryption”. There is nothing confidential about the algorithm used. But to decipher the information and retrieve it in a readable form, knowledge of a secret element is necessary: the key. This key is known to the seller's site, but not to the client, nor to potential pirates.
Any site or person wishing to receive secured communications can have its own key. From this comes an encryption procedure that anyone can use to send a message to this site or person. This is an example of a cryptographic method.
Previously reserved for the military and diplomats, cryptography is now found in mobile phones, e-mail, and even some car locking systems...
Did you know...?
The security of the best-known cryptographic methods resides in the extreme difficulty of some mathematical problems.
Theoretical progress could therefore jeopardise these methods. Some researchers are exploring a new avenue: quantum cryptography, which exploits the fundamental properties of matter.
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